RE: Temporary tables prevent autovacuum, leading to XID wraparound

> From: Michael Paquier [mailto:michael.paquier@gmail.com]
> As a superuser, DROP TABLE should work on the temporary schema of another
> session. Have you tried that to solve the situation?

Yes, we asked the customer to do that today.  I think the customer will do in the near future.

> > * In this incident, autovacuum worker misjudged that
> > pg_temp_3.fetchchunks can't be deleted, although the creator
> > (pg_rewind) is no longer active.  How can we delete orphan temporary
> > tables safely?
> 
> As long as Postgres sees that its temporary schema is in use, it would think
> that the table is not orphaned. Another thing possible would be to have
> the session now holding this schema space to reuse fetchchunks so as things
> are reset.

I understood you suggested a new session which recycle the temp schema should erase the zombie metadata of old temp tables or recreate the temp schema.  That sounds easy.

Regards
Takayuki Tsunakawa